Protecting means for furnace linings and walls



To Mair) Jfeam Generafor Feb. 26, 1929. 1,703,604

P. W. THOMPSON ETJAL rnomc'rma MEANS FOR FURNACE LININGS AND WALLS Filed May 26, 1924 '3 Sheets-Sheet 1 gwuentou W 11 0 a. 14- 55; hank Tharp 3 Sheets-Sheet 2 Smut: mps on ar/Fcr k T'kor? Othwwuj:

Feb. 26, 1929.

P. w. THOMPSON ET AL.

PROTECTING uams FOR FURNACE LININGS AND WALLS Filed May 26. 1924 L ll. ll llil L 1 i lll .U H ll llillil. L w m ln n |\l|.||||"H L m H-w-i! n L 1 I L I IWHHHHHH-H L W Feb. 26, 1929.

P. W. THOMPSON El AL PROTECTING MEANS FOR FURNACE LININGS AND WALLS Filed May 26, 1924 L L L L L U L I gwvento'w I 2" 1w son wparfir Frank Tharp Patented Feb. 26,1929. 1,703,604 UNITED STATES PATENT OFFICE.

PAUL WHEELER THOMPSON, JAMES WENTWORTH PARKER, AND FRANK THOBP, OF

- DETROIT, MICHIGAN.

rno'mc'rme IEANSIOB FURNACE LININGS AND WALLS. Amlloation fled my 20-, 1024. Serial No. 715,969.

This invention relates to furnaces and more boilers. However, in known devices of this particularly to the provision ofmeans for the nature the tube screens are connected into protection of furnace brickwork and refracthe water circulating system of the main tories against the tremendous heat resulting boiler, so that when one of the tubes of the from the burning of fuel. \Vhen solid, liquid tube screen fails, all the water in the main 60 or gaseous fuel is burned in a furnace the temboiler is unavoidably emptied out. This conperature may rise as high as 3000 F. with a dition may result in serious damage to the resulting serious effect on the furnace .brickmain boiler by overheating the boiler tubes, work and refractory material. drums or headers. In the present inven- To protect the refractories we have inventtion a tube failure will'empty the water from 5 ed a device which consists of a screen of tubes that particular tube screen only, leaving the which is so arranged in the furnace as to be boiler water circulating system unimpaired. between the hot part of the flame and the re- In the accompanying drawings in which fractories to be protected. This tube screen like reference characters designate correcarries water inside of the tubes which keeps spending parts throughout the several Fig- 7 them comparatively cool and while said tubes ures: absorb the radiant heat the refractories are Figure 1 is a transverse sectional view protected, in that they are not subjected to through the combustion chamber of a furnace the maximum furnace temperature. This having the invention applied thereto.

tube screen can also be used where the re- Figure 2 is a plan view of the screen elefractories of a furnace cover the tubes, that ments, and Figure 3 is a view partly in longiis, the refractories come between the tubes tu'linal section and partly in elevation. and the flames where either the tubes'or the ln the drawings, 5 designates the combusrefractories support the other. The tube tion chamber of a furnace and 6 the refrac- 25 screen carries water inside the tubes which tory lining thereof. There are two tube absorbs the heat imparted to the refractories screens, one upon each side of the furnace and keeps the refractories cool and below and since these two tube screens are similar their fusion point. to each other a description of one will serve This tube screen is, inasense,aboiler, since for both. Each tube screen comprises a 3 a certain amount of steam may be generated row of tubes 7, the major portions of which in it, but its primary function is to protect lie within the combustion chamber and befurnace walls, linings and refractories. One tween the point of maximum heat and the of the principal features of this device is that refractory material 6. The lower portions its water circulation system is entirely indeof these tubes are bowed, as indicated at 8 pendent of a main steam generator, retort, and extend outwardly through the furnace or other device whereby steam is generated or walls at 9 the bowed portions of these tubes heat absorbed. The steam generated in this are staggered, as shown. This facilitates tube screen may, however, discharge into the circulation of the gases through and about main steam generator, retort or other device, these portions of the tubes and also aids in 40 or into steam mains, whereby the steam is preventing accumulation of ash on said used for heating, power or other industrial tubes. The ends of these outwardly extendpurposes. All heat absorbed by this tube ing portions are connected at 10 to a drum screen is thereby saved. One of the principal or header 11. The upper ends of the tubes applications of this device is to protect the 7 extend outwardly through the furnace walls 45 furnace lining and bottom of the furnace and are connected to a relatively large drum when burning pulverized fuel. If such a deor header 12. Return tubes 13 extend from vice is not used the high temperature may the bottom of the drum 12 to, and enterthe result in serious deterioration of the furnace top of drum 11. The drum 11 not only serves I brickwork and the ash in the coal will melt as a common connecting means between the or become soft (fused or partly fused) and lower ends of tubes 7 and 13 but it serves as stick to the sides or the bottom of the furnace, a blow-off or a mud drum and to that end is where it will gradually build up into a solid provided with a blow-off connection at 14.

mass. \Ve are aware of the fact that it has Each drum 12 is provided with a main steam heretofore been proposed to locate screens of outlet 15 which may be in communication 5 water carrying tubes in the furnaces of steam with the main steam space of the boiler duced to atomospheric proper, or the steam may be directed any other desired point. For purposes of 1llustration I have indicated two valves, 16 and 17, connected to a T 18, said T 18, being in turn, connected to outlet 15. The valve 16 being open and valve 17 belng closed, steam from the drum 12 may pass to the steam space of the boiler, or if valve 16 be closed and valve 17 be open, the steam may be directed to any desired point or even to the atmosphere. By virtue of this arrangement the steam generated in the screens may be delivered to the boiler and utilized along with the steam generated by the boiler. However, if onset the tubes 7 should become impalred, the pressure upon the screen could be reby closing valve 16 and opening valve 17. A leak which would be a severe one under boiler pressure, might show up very little, or not at all, under no pressure. Thus it would be possible to keep the entire screen in operation until a convenient time could be found for the repair of the faulty tube.

Outlets 19 and 20 upon the ends of the drum 12 provide means for the attachment of water-columns, from which the water level in the system may be readily ascertained, one of said water columns being indicated at 21. It is manifest that if the water screen system is to be independent of the boiler water supply, means must be prov1ded tor supplying water to said system. To this end we provide in the ends of the drums 12, connections 22 and 23 which serve to receive the two branches 24 and 25 of a feed water line. Connection 23 is a main feed water connection, and connection 22 is an auxiliary feed water connection. The branch 24 extends along and lies within a troughlike member 26 and has a plurality of evenly spaced holes in its bottom. The branch 24 joins branch 25 at a point about half way along the length of the drum. By virtue of this arrangement the feed water is delivered at a uniform temperature throu bout the length of the drum. A feed regu ator connection is indicated at 28 upon the end of each of the drums. Branches 29 and 29 of an outlet 30 serve to receive conventional safety valves.

Among the important advantages of the arrangement herein shown and described the following are to be particularly noted. The

tubes are extended transversely of the fur-' nace and com lementally substantially span the same. T eir bowed ortions are disposed substantially central y of the furnace, below the zone of highest temperature. bowing of the tubes in the manner indicated increases the effective length of those portions of the tubes, and provides a relatively large area of heat absorbing surface in the central region of the furnace below'the zone of combustion. The net result is that the The cooling efi'ect on the ash is greatest where most needed, while, at the same time, the capacity for steam generation is increased.

It is further to be noted that the drums 12 are more than mere headers. That is, they are truly drums in the sense that they are of such capacity as to constitute reservoirs for a considerable quantity of water. If these elements were mere headers there would be such constant agitation and ebullition of the water therein as would result in the passage of a very moist steam to the main boiler from these drums. By making the drums of con-- siderable capacity, and maintaining a considerable body of water therein, a much drier steam can be delivered from said drums to the main boiler. Further, the maintenance of this considerable quantity of water in the drums insures an adequate supply of water for the "several tubes of a screen and pre-' vents their becoming burnt. It is important to note that the arrangement proposed is such that a local circulation will be maintained in each of the tube screens. While it is possible to deliver the steam generated in these auxiliary boilers to the steam space of the main boiler, nection between the main and auxiliary boilers goes; the circulation in the auxiliary boiler is wholly independent of the circulation in the main boiler, and this is a feature of advantage Whether the feed water supply be independent of the main boiler or not. The local circulation in the auxiliary boilers or water screens results in depositing whatever mud or other impurities may be present in the system, in the mud drums 11, and since these mud auxiliary boilers may be kept unimpeded at all times, wholly independent of the condition of the main boiler.

It is to be understood that the invention is not limited to use in connection with furnaces wherein the refractory material lies at an angle and indeed it is not limited to use in connection with any particular type of furnace whatever. On the contrary it is intended to cover broadly a means for providing a tube screenthat is independent of the main circulatory system of a steam generator, retort or other device, irrespective of type, whereby steam is generated or heat absorbed, and also irrespective of the type of furnace to which this screen may be applied and irrespective of the particular arrangement of the piping and other elements of the screen. Consequently it is to be understood that the invention includes within its purview whatever changes fairly come within the terms or the spirit of the appended claims.

Having described our invention what we claim is:

1. The combination with a steam boiler drums are provided with blowoils 14, it follows that the circulation in these that is as far as the con- I tubes of each furnace having opposite side walls, the major portions of which lie at an inclination with respect to the vertical, of a water screen for each of said 'side walls, each of said screens comprising a plurality of bowed tubes disposed in a row along the correspond ing side wall and close enough together to constitute the said screen for the adjacent side wall, said tubes lying laterally of said wall and haying their upper and lower ends projected through said wall, a horizontal drum extending lengthwise of the furnace outside each of the side walls with which the upper ends of said tubes are connected, horizontal headers extending longitudinally of the furnace to which the lower ends of the tubes are connected and return tubes between the drums and headers, the bowed portions of the opposed sets of tubes lying adjacent each other.

2. A structure as recited in claim 1 in combination with a perforated feed water pipe extending longitudinally of each of the drums, said pipes being independent of the feed water supply of the boiler and being perforated to discharge feed water at a plurality of points throughout the length of the drums to equalize the temperature of the water fed to the several tubes.

3. In a device of the character described the combination with the combustion chamber of a steam boiler, of a plurality of screen tubes extending transversely of thecombustion chamber and lying in spaced relation to the side walls thereof and comprising bowed portions atthe lower port-ion of the combustion chamber, the bowed portions of alternate tubes being staggered with respect to the corresponding portions of the intermediate tubes and means for feeding water to said tubes independently of the circulatory system of the boiler.

4. The combination with the combustion chamber of a steam boiler furnace of a pair of" screens comprising a pluralit of water tubes extending laterally of an overlying the walls of the said chamber at each side of the furnace and lying in spaced relation to said walls, each of said tubes comprising a bowed portion at the bottom of the combustion chamber, the bowed portions of the screen being arranged in staggered formation to form alternate projected and retracted portions, the projecting tubes ofone screen being opposed to the retracted tubes of the other screen and means for feeding water to all of said tubes independently of the circulatory system of the boiler.

5. The combination with the combustion chamber bra steam boiler furnace and its refractory-side walls. of a water screen extending along opposite walls of the furnace,

each of said screens comprising a plurality of bowed tubes which extend laterally of and lie in spaced relation to the respective wall of the furnace, a drum outside each of said opposite walls, the upper ends of said tubes of each screen passing through the correspond ing furnace wall and being connected to said respective drum, a mud drum outwardly of each of said opposite walls to which the lower ends of said tubes or said screen are connected, return tubes connecting each drum and the corresponding mud drum, means for feedingwater to said drums and tubes 'independently of the circulatory system of the boiler, and means for connecting said drums to the circulatory system of the boiler, the bowed portions of the opposed sets of tubes lying adjacent each other.

6. The combination with a steam boiler furnace having a side wall, of a. water screen for said side wall comprising a longitudinal row of tubes, each of said tubes having an intermediate portion disposed within the furnace and upper and lower end portions which bass thrdugh the side wall to the outside of the furnace, the intermediate portions of the tubes overlying the side wall in spaced relation thereto and extending in a generally vertical direction, a horizontal drum extending lengthwise of the furnace and outside the sidewall with wl'iich the upper ends of the tubes are connected, a horizontal header outside a lower portion of the wall to which the lower ends of the tubes are connected, retui .l tubcsbet-ween the drum and header and means for supplying feed water. to said drum independently of the circulatory system of the boiler.

7. In combination, a main boilercombustion chamber having refractory walls, a combined auxiliary boiler and water screen for the combustion chamber wall comprising a longitudinal row of screen tubes within the combustion chamber, extending substantially throughout the length of the combustion chamber disposed in a generally vertical direction and lying in such spaced relation to each other, and in such spaced relation to the refractory walls as to pcrmitfree circulation of the products of combustion there-around, return tubes outside the combustion chamber, a chamber lying wholly outside of said combustion chamber constituting a steam space and a common connecting means between the upper ends of the screen and return tubes, means for establishing connection between the lower ends of the screen and return tubes, and a feed water supply for the auxiliary boiler,which is wholly independent of the circulatory system of the main boiler, the generally vertical disposition of the screen and return tubes being such as to inducea local circulation in the auxiliary boiler that is wholly independent of the circulatory system of the main boiler. I

8. In combination, a main boiler combustion chamber having refractory walls, a comspective tubes so that a chamber iary boilers associated therewith, each comprising a series of bowed tubes spaced longieach side thereof, a

neon connecting means between the upper bined auxiliary boiler and water screen for the combustion chamber wall, comprising a. longitudinal row of screen tubes within the combustion chamber extending substantially throughout the length of the combustion chamber, disposed in a generally vertical direction, and lying in such spaced relation to each other, and in such spaced relation to the refractory walls as to permit free circulation of the products of combustion therearound, return tubes outside the combustion chamber, a chamber lying wholly outside of said combustion chamber, constituting a steam space, and a common connecting means between the upper ends of the screen and return tubes, means for establishing connection between the lower ends of the screen and return tubes, and a feed water supply for the auxiliary boiler which is wholly independent of the circulatory system of the main boiler, the generally vertical disposition of the screen and return tubes being such as to induce a local circulation in the boiler that is wholly independent of the circulatory system of the main boiler, and means for conducting steam from the steam space of the auxiliary boiler to the main boiler.

9. The combination with the combustion chamber of a main boiler, 01 a pair of auxiliary boilers associated therewith, each including a series of bowed tubes spaced longitudinally along the combustion chamber of the furnace, with their upper and lower end portions projected through the walls of the furnace and with their bowed ortions disposed substantially at the center line of the furnace and near the bottom thereo 10. The combination with the combustion chamber of a main boiler, of a pair of auxiliary boilers. associated therewith, each including a series of bowed tubes spaced longitudinally along the combustion chamber of the furnace, with their upper and lower end portions projected through the walls of the furnace and with their bowed portions disposed substantially at the center lineof the furnace and near thebottom thereof, and means disposed upon the exterior of the furnace for establishing communication between the upper and lower end portions'of the re be maintained therethrough. j 11, The combination with thecombustion of a main boiler, of apair of auxiltudinally along the combustion chamber of the furnace, with their upper and lower end portions projected 'through the walls of the urnace and with their bowed portions disposed substantially at the center line of the furnace and near the bottom thereof, return tubes disposed exteriorly of the furnace upon drum constituting a comlocal circulation mayv causedto constitute true the main boiler, capable of independent circu ends of the first named tubes of each boiler, and the return tubes, and a mud drum constituting a common connecting means in each auxiliary boiler. between the lower ends of the return tubes and the lower ends of the first named tubes. y

12. A structure as recited in claim 9, where in the bowed portions of the tubes of each aux iliary boiler are staggered, with the projected tubes of one auxiliary boiler disposed opposite to the retracted tubes of the opposite auxiliary boiler, and vice versa.

13. The combination with the combustion chamber of a main boiler adapted to burn fine fuel in suspension and having downwardly conver ent refractory walls, of a pair of auxiliary boilers associated therewith, each of which comprises a series of tubes, the intermediate portions of which are bowedand the upper and lower end portions of which are projected to the exterior of the furnace, the bowed portions of the tubes of one auxiliary boiler being disposed in juxtaposition to the bowed port-ions of the tubes of the other auxiliary boiler, and substantially at the center of the furnace, the upper runs of said tubes being downwardly divergent from said refractory walls, and the tubes of each boiler being disposed in spaced relation to each other along the len th of the furnace.

14. structure as recited in claim 13, in combination'with a drum for each auxiliary boiler disposed outside of the furnace and to which the upper ends of all of the tubes of said boiler are connected, return tubes for each boiler leading from the bottom of said drums, and a mud drum for each stituting a common connecting means between the return tubes of that boiler and the lower ends of the first named tubes.

15. In combination, a combustion chamber, two rows of tubes at the bottom of thechamber extending inwardly and downwardly to about the middle portion of the chamber, one row extendin inwardly from one side of the chamber, an the other row extending inwardly from the opposite side of theehamber, the lower ends of the tubes passing to the exitremity of the combustion chamber, means connecting the outer ends of the tubes so that an independent local circulation may take place therethrough, and a feed water supply auxiliary boiler confor the tubes that is independent of the feed water supply of the boiler with which the tubes are associated, so that said tubes are boilers auxiliary to lation and capableof maintenance of a feed water supply therein independent of the circulation of the main boiler. e

In testimony whereof we hereunto afiix our signatures.

P. W. THOMPSON, J. W. PARKER. FRANK THORP. 

